Silicon carbide is a promising material for high temperature, high power and radiation resistive electronic devices. This application is due to its unique properties of large band gap, high break down electric field, high electron mobility and high thermal conductivity. SiC exhibits more than 250 polytypes, in either hexagonal (.alpha.) or cubic (.beta.) form, depending on the stacking order of silicon and carbon atoms. Among these polytypes, 6H-SiC has received more attention because it is easier to prepare.
Various growth techniques, including chemical vapour deposition (CVD) and physical vapour deposition (PVD) have been reported to successfully provide oriented growth of .beta.-SiC. For example, Powell et al. (Applied Physics Letter, 56, p. 1442, 1990) have reported oriented growth of .beta.-SiC on silicon using microwave CVD with SiH.sub.4, C.sub.3 H.sub.8, and H.sub.2 as the feeding gases. However, this process requires a high substrate temperature (&gt;1300.degree. C.) which is quite close to the melting point of silicon. This can result in film contamination and hydrogen incorporation. Besides, a deposition system of very high safety standard is required because propane is flammable and silane is pyrophoric. On the other hand, Rimai et al. (Applied Physics Letter, 59, p. 2266, 1991) reported epitaxially oriented growth of .beta.-SiC by laser ablation of a ceramic SiC target at a substrate temperature held below 1100.degree. C. While this method does not suffer from the problems of the microwave CVD method, large area .beta.-SiC film cannot be produced.
The present invention provides a method for producing large area heteroepitaxial .beta.-SiC films on silicon at a lower substrate temperature without using flammable and toxic gas sources.